iPhone vs. Android via USB-C sound quality difference is huge

[XTF1]

You can send analog audio through USB-C? Interesting. Never heard about it. Do you have more information on that? What standard is it?

There is a USB-C audio (analog) standard. This audio-over-USB is hardly used by anybody, but it is part of the USB specifications standard.

The USB standard also includes options for the OEMs to re-purpose some of the USB-C pins—which ones is defined in the spec. It’s a “standard” option to develop a “proprietary” USB connection. For example, my Mark Levinson 5909 has a special 3.5mm to USB cable. It’s 3.5mm analog on one end, USB-C on the other end, connected into the same USB port used to charge the HP or have a direct, digital connection to a laptop for example (then it is seen as a sound card). The 3.5mm to USB cable is “proprietary”, but it meets the USB-C standard specifications.

 

[BS5711]

It’s actually an Apple-imposed restriction: iOS doesn’t expose USB (or Lightning) low-level communication API. Until Apple changes that (rumor is that it’s coming), there is nothing Moondrop can do about it.

Different specific subject but possibly related to the above restriction.

Could the above restriction explain a scenario I encountered ?

Using an Android DAP as a USB source into a Schiit Modi plus DAC while using a separate USB power supply to power the DAC reduced the DAP battery drain per hour by 75% versus the DAP providing USB power which seems about what might be expected.

Doing the same thing with an iPhone 15 or an iPad mini only reduced the battery drain per hour by only 25%.

I don’t understand the technicalities of USB protocols but it seemed like the iPhone and iPad didn’t communicate with the DAC as well as the Android DAP did and was being called on to provide more power than it really needed to considering the DAC had it’s own power supply.

 

[XTF1]

Different specific subject but possibly related to the above restriction.

Could the above restriction explain a scenario I encountered ?

Using an Android DAP as a USB source into a Schiit Modi plus DAC while using a separate USB power supply to power the DAC reduced the DAP battery drain per hour by 75% versus the DAP providing USB power which seems about what might be expected.

Doing the same thing with an iPhone 15 or an iPad mini only reduced the battery drain per hour by only 25%.

I don’t understand the technicalities of USB protocols but it seemed like the iPhone and iPad didn’t communicate with the DAC as well as the Android DAP did and was being called on to provide more power than it really needed to considering the DAC had it’s own power supply.

Maybe… I don’t know anything about Schiit’s Unison USB bridge. It’s an in-house development, UAC 2.0 compliant, based on a NXP (?) MCU. The USB audio protocols & communication should be the same whether it’s plugged to an Android DAP or iPhone, but how the power is managed: a question for Schiit?

 

[BS5711]

Maybe… I don’t know anything about Schiit’s Unison USB bridge. It’s an in-house development, UAC 2.0 compliant, based on a NXP (?) MCU. The USB audio protocols & communication should be the same whether it’s plugged to an Android DAP or iPhone, but how the power is managed: a question for Schiit?

Thank you.

 

[gregorio]

Mostly they are just so much more powerful, precise and more stable which leads to better dynamics.

They are not more precise or stable leading to better dynamics, if anything, the opposite. The Apple dongle is also well reasonably well powered outside the EU, certainly enough to drive many IEMs to potentially hearing damage levels. Inside the EU, they have half the output (0.5V) but that’s due to EU laws designed to reduce noise induced hearing loss.

So you think everyone on this planet using a different dongle than the Apple 9$ dongle has expectation bias? Interesting.

Assuming everyone on this planet is a human, then yes, I’d expect everyone to have expectation bias. Do you know someone who isn’t human or is human but has no expectation bias?

G

 

[2leftears]

They are not more precise or stable leading to better dynamics, if anything, the opposite. The Apple dongle is also well reasonably well powered outside the EU, certainly enough to drive many IEMs to potentially hearing damage levels. Inside the EU, they have half the output (0.5V) but that’s due to EU laws designed to reduce noise induced hearing loss.

Another example of well-intended but totally messed-up legislation; clearly they never heard of different headphone impedances and sensitivities.

 

[gregorio]

Another example of well-intended but totally messed-up legislation; clearly they never heard of different headphone impedances and sensitivities.

On the one hand there were some quite large scale independent studies showing that youngsters were demonstrating more noise induced hearing loss since IEMs became common, on the other hand was the fact that an extremely small percentage of people were using esoteric, audiophile IEMs. So it was really a bit of a “no brainer” taking the bigger picture into account and even 0.5V can still drive many/most IEMs above safe levels. Not so good if you’re one of that extremely small percentage though.

G

 

[OhGosh]

New development: after switching to what I'm 100% sure is an OTG adapter that just arrived through the mail, I can say that I can't hear much of a difference at all.

Not sure if what I was hearing was due to a bad adapter, if the one I was using before wasn't OTG or if it was just a placebo thing. It's pretty hard for me to tell.

What I can say is now I can enjoy using apple music on my actual iPhone without feeling like I'm missing out. Which is pretty good.

Sometimes I still feel I hear a difference but it's very subtle that it could just be volume, or just be nothing at all.

Gave my old adapter to my wife as she sometimes forgets to take her iphone charger and having that adapter can make life easier. This new one will live inside the May's case cause it'll be my main way of listening to it now.

 

[lindijones]

Short update:

Moondrop released a firmware update for the Dusk DSP cable.

=> now it sounds pretty similar on iPhone vs. Android.

Whatever they fixed.

 

[2leftears]

Short update:

Moondrop released a firmware update for the Dusk DSP cable.

=> now it sounds pretty similar on iPhone vs. Android.

Whatever they fixed.

A firmware update for a cable.

It is the 21st century

I'm getting old

 

[bigshot]

Why would anyone want a DSP in a cable?

 

[gregorio]

A firmware update for a cable.

Why would anyone want a DSP in a cable?

It’s not a cable. Very unfortunately, some manufacturers/retailers/marketers are referring to cables with built in processing, say DSP/DAC chips or other active components as just “cables”. So, they could call say the Apple Dongle a “cable”, even though it’s actually a DAC attached to two cables. Fortunately, Apple doesn’t market it that way. Others aren’t so scrupulous!

G

 

[OhGosh]

Why would anyone want a DSP in a cable?

Cause then you can carry around your own pEQ settings conveniently and use it in whatever you want without having to fiddle with anything or carry many things with you.

May not be the best thing but it's valid. If you already have a music player with pEQ there's no real reason to use it, but pretty much 99% of people just use their phones.


On an unrelated note, I liked the May so much I bough the Dusk and I love it. Not sure if the firmware is updated or not, I'll check it eventually.

I'm not heaving much of a difference between my iphone and android devices on anything except Dolby Atmos songs. I figure maybe the whole difference thing might be how apple devices deal with spatial audio. I know there's a thing on iPhone to scan your head to better adjust it to your anatomy, maybe that could be it. Who knows.

If it's not recorded in atmos, I honestly hear no difference.

EDIT: Yeah just checked mine already has the most recent update, so that might be the reason I hear no difference too.

Still hear differences in atmos content though.

 

[2leftears]

Well, the possibilities are endless.

500Gb or even larger flash-memory chips are tiny. The entire music library could be stored in the cable

In fact the entire music library could be stored in the headphones. A Bluetooth-connected app on the phone could control the library browsing, whereas the actual playback & D/A conversion could all happen inside the headphones, no need to stream the actual audio data over a cable or Bluetooth. Maybe that already exists (not too familiar with the latest streaming/playback tech).

 

[bigshot]

Throughout this thread, I had no idea what was being discussed because the wrong word was being used. Of course a difference in sound between two devices might likely be due to a software issue in a DSP. But a "cable" shouldn't be having software issues.